fighting cats- help!

[Becky]

DH and I have two cats- one male and one female, about a year apart in age. Both are rescues and come with a certain amount of bagagge. The male was rescued from a hoarder's house (so we're told) and is very gregarious, attention-seeking, and outgoing. The female was a stray who lived under a barn for a few months and spent another few months living at the vet's office. She is shy, aloof, and suspicious. They've mostly existed peacefully for the past 8 years, although we've tolerated the occasional fight.

However, recently, the fighting has escalated. From a "pounce-swat-hiss and done" to full-on body blows and quite a bit of yowling from the pouncee. The male is the instigator every time, and it seems to be in conjunction with wanting something (food or attention). They are fed in separate rooms, and we have 3 litter boxes. So no conflicts there...

I'm ready to separate them and re-introduce them. Anything to re-establish some level of tranquility. Any ideas or advice on how to best resolve the conflict?